Optical polymer element for coupling photoelements onto integrated-optical circuits

Abstract

An integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical coupling element into the photoelement, wherein the photoelement (23) is incorporated into a polymeric upwardly closed cover plate (51), the cover plate (51) is fitted exactly onto a base plate (50) having an optical waveguide (20), and the coupling element is an optical buffer layer (54) disposed between the cover plate (51) and base plate (50). Preferably, the buffer layer (30) has a refractive index in the region opposite the photoelement (23) which is less than or equal to the refractive index of the optical waveguide (20), but greater than the refractive index of the buffer laser (30) outside the region opposite the photoelement (23).

I claim: 
     
       1. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the entire buffer layer has a lower refractive index than the lightguiding polymer layer. 
     
     
       2. An integrated-optical device according to claim 1, wherein the buffer layer is optically changed locally over a sensitive window of the photoelement such that the evanescent light fields extend locally far beyond the buffer layer and into the photoelement. 
     
     
       3. An integrated-optical device according to claim 1, wherein the refractive index of the buffer layer is raised, by local ion diffusion or ion implantation, in the region of a sensitive window of the photoelement. 
     
     
       4. An integrated-optical device according to claim 3, wherein the degree of optical coupling is set via the height of the index change of the buffer layer. 
     
     
       5. An integrated-optical device according to claim 1, wherein a polymer layer with photopolymerizable additives, the refractive index of which is set locally over a sensitive window of the photoelement by UV exposure, is used as the buffer layer. 
     
     
       6. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a polymeric base plate having an optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and base plate; the buffer layer is a polymer layer with photopolymerizable additives responsive to UV exposure and whose refractive index is set locally in a region opposite a sensitive window of the photoelement; the refractive index gradually changes spatially due to UV exposure, in varied density, such that the refractive index profile of the buffer layer is set in a longitudinal direction of the waveguide or as a spatial depth profile of a refractive index increase over the sensitive window of the photoelement. 
     
     
       7. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the buffer layer is structured in the lateral direction in a region opposite a sensitive window of the photoelement by a taper structure having a slightly increased refractive index. 
     
     
       8. An integrated-optical device according to claim 7, wherein the taper structure runs to a point. 
     
     
       9. An integrated-optical device according to claim 1, wherein the optical buffer layer allows an optical coupling with the optical waveguide only in a region of a sensitive window of the photoelement. 
     
     
       10. An integrated-optical device according to claim 1, wherein the optical waveguides comprise higher-refractive-index polymers incorporated in structures formed as grooves in the polymeric base plate. 
     
     
       11. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; the optical buffer layer, with photopolymerizable admixtures, is applied to the cover plate; and the refractive index of the buffer layer in a region opposite a sensitive window of the photoelement is raised and set in at least one of the longitudinal direction of the waveguide, as a spatial depth profile of the refractive index increase, and as a taper structure by local UV exposure. 
     
     
       12. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the optical buffer layer is formed as a thin polymer film having electrical conductor tracks on a side facing the cover plate; and this buffer film with the electrical conductor tracks is laminated onto the cover plate such that the photoelements are electrically contacted at the same time. 
     
     
       13. An integrated-optical device according to claim 12, wherein the refractive index of the buffer film is raised locally in the region opposite a sensitive window of the photoelement. 
     
     
       14. An integrated-optical device according to claim 12, wherein the degree of optical coupling is set via the refractive index. 
     
     
       15. An integrated-optical device according to claim 13, wherein the refractive index of the buffer layer has different magnitudes in at least one of laterally and vertically. 
     
     
       16. An integrated-optical device according to claim 12, wherein the optical buffer layer comprises an embossed thermoplastic film. 
     
     
       17. An integrated-optical device according to claim 12, wherein the optical buffer layer has a smaller layer thickness locally in a region opposite a sensitive window of the photoelement. 
     
     
       18. An integrated-optical device according to claim 12, wherein the optical buffer layer carrying the electrical conductor tracks extends beyond the outer dimensions of at least one of the cover and base plates and has electrical contacts there. 
     
     
       19. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and a light entry surface of the photoelement is geometrically closer to the optical waveguide than the cover plate and extends partially into the buffer layer. 
     
     
       20. An integrated-optical device according to claim 19, wherein the light entry surface is covered by a semiconductor layer which has a higher refractive index than the optical waveguide, and draws the evanescent light fields out of the optical waveguide and feeds them to a light-sensitive junction of the semiconductor layer for detection. 
     
     
       21. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the optical waveguide is produced in a base plate formed of organic polymer film; and the photosensitive side of the photoelement is adhesively attached by a higher-refractive-index transparent adhesive, which forms the buffer layer, directly onto the optical waveguide. 
     
     
       22. An integrated-optical device according to claim 21, wherein-the degree of optical coupling is set by choice of the refractive index, the thickness and the length of the polymer adhesive. 
     
     
       23. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the coupling distance is set via spacers arranged between the polymer base plate receiving the optical waveguide and the photoelement. 
     
     
       24. An integrated-optical device according to claim 23 wherein the spacers are formed by conductor tracks thickened by electroplating, applied to the photoelement. 
     
     
       25. An integrated-optical device according to claim 21, wherein the adhesive at the coupling location simultaneously serves to mechanically fix the photoelement to the base plate and waveguide. 
     
     
       26. An Integrated-optical device in polymer technology, having a photoelement coupled onto an optical waveguide, with only the evanescent field components of the optical waveguide being coupled by an optical intermediate element into the photoelement, and wherein: the photoelement is incorporated into a polymeric upwardly closed cover plate; the cover plate is fitted exactly onto a base plate comprising a polymer layer having a light guiding optical waveguide; the intermediate element is an optical buffer layer disposed between the cover plate and the base plate; and the optical waveguide is encapsulated together with the coupled-on photoelement by a lower-refractive-index covering layer. 
     
     
       27. An integrated-optical device according to claim 26 wherein the buffer layer has a refractive index in a region opposite the photoelement which is less than or equal to the refractive index of the buffer layer outside the region opposite the photoelement. 
     
     
       28. An integrated-optical device according to claim 1 wherein the buffer layer has a refractive index in a region opposite the photoelement which is less than or equal to the refractive index of the buffer layer outside the region opposite the photoelement. 
     
     
       29. An integrated-optical device according to claim 21, wherein the coupling distance is set via spacers arranged between the polymer base plate receiving the optical waveguide and the photoelement.